Project Background: According to IOM, high quality care is safe, effective and patient centered. Initiatives such as Choosing Wisely, a program to de-implement low value practices, can provide an effective message to simultaneously improve quality and value. However, while Choosing Wisely identifies targets for de-implementation, it does not speak to what strategies may help achieve this goal. While much is known about effective implementation strategies, little is known about effective de-implementation strategies. This is important because active de- implementation likely entails different dynamics, and unintended consequences, than implementation. VA operational partners in Pharmacy Benefits Management and Office of Specialty Care Services have helped identify and prioritize an initial set of common clinical practices that should be de-implemented. Project Objectives: Our overall goal is to improve healthcare delivery, safety and value for Veterans and VHA, consistent with multiple strategies outlined in the VA Blueprint for Excellence, by working with our partners in the Office of Specialty Care and Pharmacy Benefits Management to de-implement low value practices. We propose a series of experimental and quasi-experimental quality-improvement projects that compare the effectiveness of alternative de-implementation strategies: strategies based on changing clinician information and knowledge, and strategies based on providing tools and substitutes to the harmful practices. Our specific aims are to: Aim 1. Work with key operational leaders to identify and prioritize diagnostics and therapeutics that are ineffective, contraindicated, or of low value to patients, and develop de-implementation strategies that work in concert with operational strategies and policies. Aim 2. Test the effectiveness of de-implementation strategies to reduce ineffective, contraindicated or low value diagnostics and therapeutics. Aim 3. Develop the science and taxonomy of de-implementation by assessing the impact on de- implementation from (a) clinicians' perception of the evidence about ineffective practices, (b) clinicians' professional efficacy, and (c) clinics' organizational context. Aim 4. Assess the budget impact of de-implementation strategies in order to inform dissemination. Project Methods: We will test de-implementation strategies for four clinical practices spanning multiple specialties and patient populations, including both therapeutic and diagnostic practices. In each project, we will test the effectiveness of de-implementation strategies alone and in combination, and will assess the budget impact of fielding de- implementation strategies. Built on the structure of our successful and longstanding QUERI/Office of Specialty Care Evaluation Center, we will incorporate a mixed-methods formative evaluation to assess barriers and facilitators, and identify potential unintended consequences of the de-implementation strategies. We will assess changes, before and after employing de-implementation strategies in participating clinicians' perceptions of the empirical evidence against the ineffective practice; clinicians' intent to reduce the ineffective practice; and professional inefficacy (a component of work-related burnout). We will also assess key components of organizational context, such as culture of change among leaders and staff. We will assess organizational context as a moderator of de-implementation strategy effectiveness across clinical settings and practice changes. By doing this we will contribute to the science and taxonomy of de-implementation by developing, testing and refining a conceptual model of de-implementation.